Improvement in middlings-purifiers



" theiscreen from clogging matter.

UNITED STATES PATENT QEEIcE EDWARD I. WELCH, OF GEORGETOWN, DISTRICT OF COLUMBIA, ASSIGNOR TO HIMSELF, JAMES H. WELCH, ROSIA W. WELCH, HERBERT P. WELCH,

AND JAMES A. MALONEY, OF SAME PLACE.

IMPROVEMVENT IN MlDDLlNGS-PURIFIERS.

Specification forming part of Letters Patent No. 135,95 3, dated February 18,1873.

To all 'whom it may concern:

Beit known that I, EDWARD PRICE WELCH, of Georgetown, in the District of Columbia, have invented certa-in new and useful Improvements inMachinery for Purifying Middlings, of which the following is a speciication:

My invention relates to that class of machinery for dressing iour in which a current of air is passed throughfscreeus to sift and separate the various qualities of iour, and a brush is used to clear the meshes of the screens.

The subject-matter'of my improvement is hereinafter specified.

In the accompanying drawing, Iigure 1 represents a vertical longitudinal section 5' and Fig. 2, a vertical transverse section through a middlings purifier embracing my improvements.

The construction of the various parts of the machine being well understood by skillful constructors of milling-machinery, their details Ineed not be particularly described here.

A screen, A, is suspended by radius links a, and vibrated by an eccentric, B, or other suitable means. Beneath this screen I mount a rotary brush, C, on an axis perpendicular to the face of the screen, and drive itby suitable belts or gearing, so that it may rotate across the face ofthe screen, which at the Sametime is vibratingacross the brush, thus producing a diagonal drawing movement which I have found very e'ective in clearing the meshes of Any number of brushes desired may be used according to the requirements of the particular case. Instead of a simple brush rotating on its axis, roller-brushes might be mounted on horizontal axes in the brush-head, so as to have a compound rotating motion 'both on a vertical and a horizontal axis.

In addition to the brushes, I propose sometimes io use an air-pipe, D, extending longitudinally beneath the bolt with cross-pipes D at suitable intervals. This pipehas numerous perforations to direct vfine jets of air upon both the screen and brush, and clear them of obstructions. The brushes having long and flexible bristles, readily pass over the pipes which are interposed between the brush and screen.

The pipes may be extended around the sides and ends of the screen, so as to prevent the escape of the material or to arrest its rate of discharge at the tail end. This blast, it will be understood, is independent of the ordinary one passing upward through the screen, which is also used. The ,operation of my improved apparatus will readily be understood from the foregoing description.

I do not claim a vibrating screen with a blast passing through it; nor, broadly, the combination of a screen with a clearin g-brush.

I claim as my inventionl. The combination, in a middlings-purifier, of a vibrating screen through which a blast passes in one direction while the iiour passes in the other, with a brush rotating across the face of the screen on an axis substantially perpendicular thereto, substantially as hereinbefore set forth, to produce a drawing action of the brush across the screen diagonal to its line of vibration. i'

2. The combination, in a middlings-purilier, of ay vibrating screen, brushes rotating across the face of the screen, and a perforated airpipe to direct streams of air upon the screen and brush, substantially as set forth.

In testimony whereof, I have hereunto subscribed my name. y

EDWARD P. WELCH.

Witnesses:

E. C. DAVIDSON, J 0E I. PEYToN. 

